The present invention relates to a device for the transfer of sheet metal parts in a press installation, with holding devices which hold and move the sheet metal parts being fastened as traverses on running carriages, which are movable horizontally by drives on rails and are liftable and lowerable with these rails.
Due to the increasing sizes of the sheet metal parts to be machined or larger batch sizes, transfer speeds of the sheet metal parts in the press installations, from the inserting or orientation stage through the press installation to the workpiece delivery, become continuously higher. In the past, this has resulted in transfer devices of lower masses. In addition, when the sheet metal part is rotated, because of the necessity of the removal from the tool and/or for positioning the sheet metal part in the tool that follows, a center fault of the sheet metal part will occur.
In German Patent Document DE 41 04 810 A1, a device is described for the transfer of sheet metal parts in a press installation in which the sheet metal parts, during the movement from a machining stage to a depositing device and from this depositing device into the machining stage which follows, are rotated for positioning the sheet metal parts in the tools. For this purpose, the device has traverses which are provided with suction devices. The traverses are fastened on an end face in pivot bearings of rail-guided running carriages. The travelling movements of the running carriages are press-controlled by way of a transport linkage. Correspondingly, the rails can be lifted and lowered.
Furthermore, U.S. Pat. No. 4,625,540 describes a transfer device with a frame which is guided in liftable and lowerable running rails and can be moved horizontally. On this frame, traverses can additionally be moved via adjusting devices in such a manner that, during the periods when the slide moves down, they are guided without the sheet metal part into an area between the slide and the tool for a short stoppage.
In the German Patent Document DE 39 31 081 A1, an intermediate depositing device is described for a depositing station between two machining stages of a press. The intermediate depositing device has templates for the support of the sheet metal parts which can be adjusted by adjusting devices and movement deflecting devices in their height, distance and oblique position for another sheet metal part or to a machining stage which follows. The error which is caused by the swivelling of the sheet metal part can be adjusted by the adjusting devices for the horizontal and the vertical movement of the templates.
In view of this prior art, an object of the present invention is to arrange the holding devices on the running carriages so that they can be displaced relative to them in order to, on the one hand, reduce the transfer path of the individual running carriage and on the other hand, compensate the correcting movements which are required as a result of the rotation of the sheet metal parts and which may differ from one running carriage to the next.
This and other objects are achieved by the present invention which provides a device for the transfer of sheet metal parts in a press installation comprising liftable and lowerable rails, running carriages mounted on the rails to be horizontally movable on the rails and liftable and lowerable with the rails, drives coupled to the running carriages that move the running carriages horizontally on the rails, and traverses serving as holding devices which hold and move the sheet metal parts and are fastened on the running carriages at a fastening point that is adjustable at least in a direction of the travelling movement of the running carriage.
By the adding of the adjusting movements of two moving drives of the traverse, short movements of the transport linkage can be achieved while the transfer movement is the same and the number of transfer movements is increased. When the number of transfer movements is the same, larger transfer movement lengths can be achieved.
Another important advantage of the invention is the fact that, when additional moving devices are utilized, correcting movements can be compensated, for example, those which become necessary because of the rotation of the traverse.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.